Systems that photograph a roadway or the like using a camera, detect a vehicle in an imaged image, and read in information described on a license plate, are known. Such systems may be mounted at an entrance or an exit or a toll road, for example, in order to recognize a passing vehicle. Reading information described on a vehicle license plate from a cameran image and then performing character recognition processing on the overall image may cause the processing load to become excessive, and information may not be able to be read in efficiently. Refer to JP 4690657.